Southern, if that is the case, maybe I should come over and reorganize that place. If what you describe is really happening, the whole airside division needs revamping!
First off, none of the people you mention should be out there in the first place on their own! Also, you need a dedicated escort division who's primary task is to escort contractors, police, ambulance and anyone else that does not have airport authority to be in the movement area. These persons drive dedicated vehicles with required logos and lights and are also in direct contact with ATC. And yes, even security personnel.
In essence, you NEED to have a reason to be out there on a daily basis and if your duties don't require you to be, then you are not authorized to be on even a taxiway, let alone a runway, period. Your described airport seems to be very lax with regards to who goes where and is an accident waiting to happen. I agree airports need to do more to prevent incursions. So, I have to ask, what are all these people doing out in the movement area? Do they NEED to be there? Have they passed an airport driving test? Do they know how to operate and speak on the radio? You would dramatically cut down the risk factor if they were kept to service roads on the ramp area only, nowhere else.
With regard to airfield mx, tech ops, electricians etc. at my airport, they are all trained, have radios, required badges. However, even they MUST call ops first requesting permission to go out to the movement area and also call ATC. No runway crossings! Most mx is done at night between 0200 and 0530L when one runway at a time is closed and minimal aircraft operations. Airport Ops closes and opens runways on the radio with tower, not ATC.
If you have a well-organized and trained team with everyone knowing what they need to do, you greatly mitigate the chances of runway incursions. If you let folks drive around "free range" with little control, I'm not in the least surprised on the frequency of incidents. I'd be happy to offer a few more pointers!